In the operation of construction equipment in recent years there has been a growing trend to utilize machines originally intended for a rather specific task in much more varied applications. In order to accomplish this, coupling mechanisms have been developed to allow a vehicle to mount and utilize more than one implement. For example, in the operation of a hydraulic excavator, an operator may encounter various types of soil on a single job site. When this happens, it is often necessary to change from one bucket to another or, in situations wherein rocky conditions are encountered, an entirely different implement, such as a powered hammer, may be required. In each of these situations, it is desirable to be able to detach one tool and attach the next tool and return the machine to a productive task as quickly as possible.
Several different types of quick coupling mechanisms have been utilized with varying degrees of success. One design that has achieved a great deal of success is disclosed in U.S. Pat. No. 4,854,813, issued to Robert L. Degeeter et. al. on Aug. 8, 1989. This design utilizes a wedge arrangement to couple the mounting plates of a work implement to the linkage arrangement of a work vehicle. While the wedges are arranged in linear alignment with the mounting plates and portions of the linkage arrangements, the wedges must be driven into place by means of a hammer or other suitable tool that does not maintain a positive force against the wedges while the wedges are being secured in place. This force has been known to vary somewhat and in some instances, the connection between the work implement and the linkage arrangement will loosen slightly. While this loosening is not sufficient to cause the uncoupling of the work implement, it is often necessary to re-attach the wedges to prevent their accelerated wear.
Another coupling is disclosed in U.S. Pat. No. 5,147,173, issued to Raymond L. Fauber et. al. on Sep. 15, 1992. This patent also discloses the use of a wedge to couple a linkage arrangement to a work implement. The wedge member is driven into engagement with a hydraulic actuator to maintain a positive connection at all times and has been known to work quite well. Due to the limited space that is available in the intended environment in which this coupler must operate, some of the components are arranged in a laterally offset fashion. While this is necessary to allow the design to remain compact, some forces are laterally offset from the connecting links and mounting plates. This tends to cause an uneven distribution of force applied to the wedges. It also requires many different piece parts that add to the complexity of the design and its assembly.
The present invention is directed to overcoming one or more of the problems as set forth above.